Digital system for raster scan display of video and alpha-numerics with single bit map memory

Abstract

This invention provides a simple system for simultaneous raster scan display of video and alpha-numeric data on a single screen with provision for periodic image refreshment. It includes means for encoding the electrical signals representing the spatial intensity distribution of the video signal and the alpha-numeric signal. The coded signals are stored in a single bit map memory at the desired addresses. For display, the information is simply read from the memory through a single digital-to-analog convertor.

What is claimed is: 
     
       1. A system for substantially simultaneous raster scan display of video information and alpha-numeric data on a single display comprising: first means for providing first and second electrical signals representing the location and spatial intensity distribution of a video signal respectively;   second means for encoding said second electrical signals by assigning first specified bit patterns from a first predetermined set to said second electrical signals;   third means for generating third and fourth electrical signals representing the location and spatial intensity distribution of alpha-numeric data, said fourth electrical signals being encoded with second specified bit patterns from a second predetermined set;   first memory for storing said encoded second and fourth signals at addresses determined by said first and third signals respectively; and   fourth means for sequentially reading out encoded information from said first memory including means for detecting said first and second specified bit patterns and controlling a display presentation responsive thereto whereby the spatial intensity distributions represented by said first and second specified bit patterns are visually differentiated on a display.   
     
     
       2. The system of claim 1 wherein said fourth means includes memory control means for controlling the loading and unloading of said encoded second and fourth signals into and out of said first memory respectively. 
     
     
       3. The system of claim 2 wherein said first means includes a radar receiver. 
     
     
       4. The system of claim 2 wherein said second means includes a pseudo-code generator. 
     
     
       5. The system of claim 2 wherein said third means includes a computer, second memory means for refreshing the output of said computer and an image generator. 
     
     
       6. The system of claim 4 wherein said pseudo-code generator includes: an analog-to-digital converter for transforming said second electrical signals into digital signals; and   a read only memory for assigning first specified bit patterns from a first specified set to said second signals.   
     
     
       7. The system of claim 6 including a control processor and third memory means for unloading said read only memory. 
     
     
       8. A system for substantially simultaneous raster scan display of video information and alpha-numeric data on a single display comprising: first means for providing first and second electrical signals representing the location and spatial intensity distribution of a video signal respectively;   pseudo-code generating means, for encoding said second electrical signals by assigning first specified bit patterns from a first predetermined set to said second electrical signals, including an analog-to-digital convertor for transforming said second electrical signals into digital signals and a read only memory for assigning said first specified bit patterns to said second electrical signals;   third means, for generating third and fourth electrical signals representing the location and spatial intensity distribution of alpha-numeric data, said fourth electrical signals being encoded with second specified bit patterns from a second predetermined set, including a computer for generating such data, second memory means for refreshing the output of said computer and an image generator for transforming said computer output into image form;   first memory for storing said encoded second and fourth signals at addresses determined by said first and third signals respectively; and   fourth means for sequentially reading out encoded information from said first memory including means for detecting said first and second specified bit patterns and controlling a display presentation responsive thereto wherein said fourth means includes memory control means for controlling the loading and unloading of said encoded second and fourth signals into and out of said first memory respectively, whereby the spatial intensity distributions represented by said first and second specified bit patterns are visually differentiated on a display.   
     
     
       9. A method for substantially simultaneous raster scan display of video information and alpha-numeric data on a single display comprising the steps of: transforming received video signals into encoded second signals by assigning first specified bit patterns from a first predetermined set to said video signals;   generating third alpha-numeric signals encoded with second specified bit patterns from a second predetermined set;   multiplexing said second and third encoded signals into a memory; and   sequentially reading out encoded information from said memory and detecting said first and second specified bit patterns and controlling a display presentation responsive thereto whereby video information from said received video signals encoded in said second signals with said first specified bit patterns is visually differentiated on a display from alpha-numeric data encoded in said third alpha-numeric signals with said second specified bit patterns.